Creeper tractor mechanism



G; c; JETT CREEPER TRACTOR MECHANISM Filed Sept. 27, 1922 '3 Sheets-Sht 1 George v K.

ZNVENTOR:

F b. 22,1927 JETT OREEBER TRACTOR MECHANISM Filed Sept. 27. 1922 sh ets-She et 5 JNVENTOE: Gear-gs a c/if. v

Patented F4 12, 1927.-

' I UNITEDSTAT S PATENLT-D CE I GEORGE c. JETT, or MILWAUKEE, wrsconsmfnssrenon or 'rwo-rlr'rns T WALTER H. srIEMKn, or MILWAUK E, wrsconsm.

cnnnrnn 'rnnc'ron mncnnmsiu.

Application filed Seiitember '27, 1922. Serial .No. 590,848. 4 a

a My present invention relates generally to the endless-chain tread type of tractors and ims-reference more particularly to novel improvements in the tractor'truck framework, the Supporting connections between the-truck and the tractor body, andto the steering control mechanism.

.. One'of the primary ob ects of this inven-.

,tion is to provide an apparatus or mechanism set in the form of an accessory or attachmentwhich is capable of'being substituted inplace of certain removable parts of a standard round wheel or wheel tread tractor, to thereby convert such round wheel tractor into a chain tread full creeper tractor possessing the advantages of power economy,

i freedom from soil packing and all other desirable features inherent in full creeper tractors over theround wheel type.

*Ano,ther advantageous feature of my invention" resides in 'the truck anechanisni structure which comprises a pair of truck side frame memb'ers flexibly connected together so jasto permit of vertical movements of the members relatively to each other,

. .while-latkthe same time maintaining the 'members in predetermined spaced relation.

Furthermore, the members. themselves are inherently flexible and flexibly connected to the tractor body with the result that a high degree of flexibility in the structure as a whole secured, which facilitates its easy and-rapid progress over uneven ground without subjecting the body to excessive torrequi itestrength and rigidity of structure s'ions, stressesor strains and at the same time 't'oj cnsiire satisfactory operation and lon gevit -0 the machine are maintained. A further'objectis to provide a full creeper tractor truck structure which'is in itself a 'complete assembled unit adapted 'to' be easily, quickly and conveniently attached to v *the power plant and transmission, 'or in other words, the tractor body, of several present existing designs of round wheel tractors now marketedqandused in the trade, 1 j. A frnthenfeiture resides in the 'fact that j I all of theconnections betweenfthe ,t1ucl mechzjziiisnistructure and the tractor body are made to "the body at (lesira-ble point's",

.notonlyfrom the standpoint of'convenienc'e of attachment, but also for-:purposes of strength and durability, and -in "additionthe fastenings to the truck sidel frame;

connections are so constructed as to con-.

mechanism embodying my invention, certain portions being broken away substantially on the line 1 1 of Fig. 2 to more clearly disclose certain parts otherwise concealed from view.

I Fig; 2 isa .plamview of the creeper truck for the sake of .clearness; I I Fig. 3 is" an enlarged 'detail of one of the two part sleeves used in connecting the rear I of thecreeper truck side frame members to the/tractor body; '1 Fig. i is a side elevation of the rear radius rFod anchor plate takenon-the line 7'7 of Fig. 5 is a'transverse section through the truck frame at the rear of the'side frame connecting axle, a'portion of which is broken awgiy to more clearly show the front radius ro a Y 6 and 7 are enlarged sectional and end views respectively of the connecting axle Fig. .8 is a diagrammatic view showing mechanism, one tread chain being removed the flexible truck frame in -somew hat. distorted position. Referring-in it is tobe noted that the creeper tractor mechanism forming my invention is shown more detail to the. drawings, i

in full lines, whilefor the purposes of clearness, substantially all of'the tractor struc-' ture has been omitted, only such parts being included, in the drawingas are necessary to showthe adaptation of the invention to the; tractor structure. 1 Such parts of the tractorasare-shown inv the drawingare indicated in dotted l-ines. It is who under stoodthata the invention is applicable to any of 'the well known tractor constructions, the'present embodiment of the invention,

of suitable weight, and while each may be .however, is illustrated as particularly intermediate its ends is shown in Fig. 5 and indicated by reference character 15, while the front axle 16 pivoted to the forward end of the tractor body upon. a pivot pin 17 extending through downwardly projecting lugs 18 on the body and also the rear axle 19 and its housing 21, are shown in F 2. The body itself, however, may vary widely in its structural details and the construction thereof is immaterial since the present invention is concerned merely with the creeper tractor mechanism as such and which may be modified within wide limits to facilitate its attachment to any desired type of round wheel tractor body;

My improved creeper tractor mechamsm, which is designed to replace the four wheels of a round Wheel tractor, comprises, gener ally speaking, the rear creeper sprocket wheels 24, the front creeper sprocket wheels 25, the endless chain treads 26, and the creeper mechanism frame structure, the details of which will be more fully described and .which includes the two side framesQT connected together between their ends by" the cross connecting axles 28 and 29.

The side frames 27am made of sheet metal formed from a single sheet of metal bent into substantially a U shapqit is preferable, for convenience in manufacture, to make these frames in two pieces which are connected together throughout their length by a series of rivets or bolts 31. y The side walls of each side frame are preferably stiffened by beads or ribs 32 struck up from the body of the metal and the lower edges'thereof are preferably flanged, as indicated'at 33, which increases their strength and makes a broad lower edge. The connecting web or top of each frame extending between the side walls, is cut away at its forward end as indicated by 34: in Fig. 2 to accommodate the front creeper sprockets 25, and similarly this web is removed from the rear end to a point well forwardly of the drive creeper sprockets 24 to accommodate these sprockets in the openings 35, thus provided. The inner wall of each side frame extcnds full height at its rear extremity where it. is reenforced with .an angle iron 36 (Fig. 1) to which the rear brake band clip 37 is attached,:while the I outer wall is preferably inclined downwardly from the forward end-of the opening 35 to the rear end of this wall "so as to adequatelyclear the hub of the sprocket wheel 24, the

upper edge of this well being preferably flanged over, as indicated by- 38' (Figs. 1 and 2) I 4 p Each side frame is therefore of channelshape structure, formed of sheet metal, which, while of sufficient strength to-prebe in actual practice as the result of terrene irregularities, and while this inherent flexib lity enables the tractor to accommodateitself to irregularities over which it may be traveling, each side frame 1s lnherently substantially rigid against bending movements in a vertical plane so that any liability of permanent bending or distortion of the frames or relative displacement'of the parts carried thereby is obviated, being made of sheet metal the frames are considerably lighter and therefore more desirable than cast frame structures, and in addition are much stronger proportionately to their weight than cast frames, for the reason that each portion of a cast frame must be made suliiciently strong and heavy to resist without distortion the maximum stresses to which it may be subjected, whereas the flexible sheet metal frames contemplated by my invention are by reason of their inherent flexibility capable of distributing concen trated strains throughout a considerable portion of their area so as to, oppose to the streltses an initially yielding and finally pos-' -1trve rcslstance which is not only greater or twisting movements, of each frame.

The method of connection of the two cross axles 28 andQt) with the side frames is similar for both axles, and as illustrating the connection, reference should be had to Figs. 5 to 7 inclusive, from which it Will be observed ihat each Side wall'of each side frame is perforated to loosely receive an annular head 30 formed on the axle, these heads ateach end of each axle being spaced apart to frame side walls. For the purpose of lockmg the side frames to the axles S0 as to permit a limited degree of flexibility and still correspond with the spacing of the side maintain the proper relative relations between the axles and side frames, each head is provided-just outside its side wall with a circumferential groove 41 and to the outer face of each side wall there is secured by bolts 42, a split ring comp rising the two due plicate-secti-ons 43 and 44 having relatively opposed eyes through which the bolts pass to lock theseaing sections securely to the wardly extending flanges 45 engaged in their respective grooves 41. The axles are thereby side walls. of the side frames with their insecurely,"butljfiexibly, docked to. the side frames, 'iand jfwli'ile limited flexing moveinents"'of; t he sideframes and limited move-.5

, jment of-each side wall ofthefframe toward the otheris permitted, the wo side frames as a whole are securely, butqfieXibly, connected'togethei'pwith the result that relative 'approach ng Pand separating movements of the side framesfare preclu.ded,{wh1le relative vertical m ements; as well as inherent twistingmovements, of each frame are per; mitted. J

Each side fraine'is equipped with a'plurality of pairs of bearing rollers 46 refer- .ably flanged as shown 'and dis'po'seda' jacent the outer faces, f said side frames in position to travel upon theqtrack "chain 26. whereby the weight;.of tl1e tractor is supported. Tl-iese rollers are mounted on shafts extending transversely through the side frames and carried in bearings 47 which are flexibly attached to the side frames so as not to interfere with t-he'flexing movements cups 48, or other preferred means.

' Each-front creeper sprocket-251s mounted upon ashaft 49 extendingtranwersely of the side frame, the vertical walls of which are longitudinally slotted from their forward ends to accommodate the shaft-and are strengthened at this point by U-shaped plates riveted or bolted to the side walls of the side frames; and projecting forwardly thereof where they .are'connected bybolts 52 extend 7 ing through spacing members 53 disposed between the forwardly projecting ends of each plate. The shafts 49 are adjustable longitudinally of the slotsto impose the requisite tension upon the track chain 26 by means of adjusting screws 54, and the shafts are locked in adjusted position by tightening the nut 55 with 'which'each-shaft bolt isequipped. r

The upper leg ofea'chi-nner plate 51, -i.'e., the plate mounted upon the inner Wall of the side frame,- is extended forwardly, as indicatedby reference character 56, to a position directly over an end of the front axle 16 to. which it is pivotally and flexibly'at- The bearings may be lubri-.

'now be explained. v Operative connection Festablished be tached by a linkconnection 57, as shown'in Fig. l-so that this axle and thereby the forward end of the tractor body are carried d1- 'rectly by the forward ends of' the side frames.

1- The rear ends of the side frames are connected to the rear axle housing 21 so as-to oscillate about the rear axle the connecting means being best illustrated i rltigs.1,2 and v3. Referring to these fig11rs;it \vil-l;be ob 5 served that the axle housing 21 has securely {clamped thereon atwoj-piece sleeve 58 rigidly clamped to the housing by, bolts 59 passing through the opposed eyes 61 of the twoflparts-of the sleeve and,.inorder to ensure a tight fit and afstrong clamping action of the sleeve'vupon' the,housing,-a band 62 of suit:

able textile material is preferably interposed between the sleeve and the housing.

thereby ensuring a snug, non-slipping lit;

The assembled sleeve provides ac1rcurn+ 'ferential groove 63 adapted to receive,-

be loosely embraced by, a two-part collar, comprising the lower member: 64 which is in the form of an elongated casting, indicatedgenerally by 65, securely attached to the side frames by bolts or rivets 66, an d a comple f mentary upper portion -67 connected-toflthe lower portion 64 by bolts68 at opposite Q! sides of the axle housing. 1

It will be observed, therefore, that the two-part sleeve 58 fixedly attached to the axle housing provides a bearing groove 63 adapted to accommodate the surrounding collar which is fixedly secured to the side frame and is adapted to oscillate about the sleeve as the forward ends of the side frames. 7 ,rise and fall relatively to the rear axle.

These connections between the side frames and the rear axle housing therefore afford flexibility at this point whichcontributes to the generalfiexihility of the structure as a whole and facilitates its easy travel over uneven ground wsithout imposing excessive strains and stresses upon the body of the tractor.

In addition to the connection of the tracfor mechanism frame structure to the tractor been explained, this frame structure is fur- -body through the front and rear axles as'hasther flexibly connected to the-"tractor body intermediate its ends tween the front cross c'onnecti'ng'axle 28-.and the body of the tractor through a radius rod 9 pivotally attached to the axle 28 by a bolt- 71 and pivotally connected at its other end by radius rods, as will to studs-or ears 72 extending downwardly from thebody of the tractor and adapted to receive a pin or bolt 73 which passes through an eye in the end of the radius rod. A flexible connection is thereby established between this cross connecting axle and the body which serves to retain the frame structure against lateral displacement with respect to the body, while at the same, time permlttlng vertical undulatory movements thereof.

The casting attached to one of the side frames 27 is also provided with spaced ears Tet to which one end of a radius rod is pivotally connected by a pin 76 (Fig. 2), the other end of this rod being pivoted on a pin 77 between ears78 projecting from a casting 79 adapted to be secured by the bolts employed to fasten a hand hole cover plate to the bot y. This casting also comprises an inwardly extending hollow plug 82 adapt-' ed to project into a drain opening formed in the body of said tractor, serving to lend strength and rigidity to the connection and being made hollow and adapted to receive a smaller plug which may be remoi' ed for drainage purposes. It will be apparent that the pivotal connections at the ends of the radius rods 7 5 also permit of vertical move-'' ments of the side frame structure while retaining the same against lateraldisplacement relatively to the body.

It should be apparent from the foregoing.

that I have provided acreeper tr'actor mechanism which can be readily applied to a standard round wheel tractor, thereby converting such tractor into one of the creeper type. The creeper mechanism itself is inherently flexible, since not only. does each side frame possess inherent flexibility, but

these side frames 'are flexibly connected forming a flexible frame structure. This frame structure is flexibly connected to. the

' tractor body, first, through the axles which afford a three-point suspension for the body,

the front axle'be ing pivotally connected to each side frame and the rear endsv of the front wheel steering gear is adapted to per-' wit the steering of the tractor by braking one or the other of the rear creeper driving sprockets. Furthermore, provision s made for braking both of the driving sprockets whenever occasion requires.

t is believed that my invention and many of its inherent advantages will be understood and appreciated from the foregoing without I further description, and while a 'n'eferred embodiment of the invention has been illus-' trated and described. it should he manifest that many modifications and variations of the structural details may be resorted to without departingfroi'n the essence of theinvention as defined in the following claims.

I claim:

1. In a creeper tractor mechanism, the combination of a pair of flexible sheet metal side frames of substantially inverted U- shape provided with aligned openings through the side walls thereof, a cross connecting axle extending through the openings in each side frame and provided with circun'lferential grooves adj accnt the side walls of each sideframe, and means engaging in said'groove and attached to said side walls whereby longitudinal displacement of' said axle relatively to said side frames is precluded.

2. in a creeper tractor mechanism, thecombination of a pair of inherently flexible sheet metal side frames provided with aligned openings, a cross connecting axle 8X- tending through said openings and provided with circumferential grooves adjacent the walls of said side frames,and a split ring engaged in each groove to prevent displacen'ientof said axle from said side frames.

In a creeper tractor mechanism, the combination of a'pair of inherently flexible U-shaped. sheet metal side members, provided with aplurality of sets of alined openings, a. cross-connectlng axle extendmg through each set of said openings and so connected to said side members as to permit relative torsional flexure of the side walls of eachof said lJ-shaped side members and to permit independent torsional flexure of said side members with respect to each other,v

while pre.enting relative transverse move ment of said side members with respect to each other. i

4. A creeper tractor mechanism adapted to be attached to around wheel tractor body, comprising a pair of longitudinally extending vertically disposed tl-shaped flexible metal members, each of said members car,- rying at its forward end an idler sprockets wheel, driven sprocket-wheels carried by the rear axle of the tractor body, creeper chains tralned' about each pairof sprockets, loadcarrying rollers arranged along the-lower edge of said U-shaped metal members, means for sn ortin said rollers'in the side walls of said U-shapedmetal members, and means interconnecting said ll-shaped side members,

said roller supporting means and intercomnocting means being arranged to permit relative flexure of the side walls-of each of said U-shapcd metal members and permitting relative flexure of said U-shaped members withrespect to each other, means for securing said tractor body to said-U-shaped members, saidlast mentioned means construtted to permit vertical oscillation of said U- shaped members and additional means for preventing lateral displacement of said trac-' tor body with respect to saidfU-shaped members.

5. A-creeper tractor transversely extending members interposed intermediate the length of said side mem-" bers, 'meansfor connecting said transverse members andjfside members,- said last mentloned means. permittingnndependent tormechanism adapted to be'attachedto a-round wheel tractor body to replace the round -Wheels thereofi omprising a frame structure, including. a air of longitudinally extending side 'mem ers,-.

sionaljflexure' .ofsaid s1de members, whilepreventing lateral movement thereof, means forpivotally supporting the rear end of each of said side -members upon the rear axle.

. housing of said tractor body, said pivotal supporting'means including complementary v clamping members adapted to be attached to 20 T and roject beyond the ends of said rear axle housing and means for flexibly connecting the forwardend of each of said side members tothe associated end of the front axle of p nd ertical oscillation and :torsional ,flexurQ o said side members.

said tractq o y to Permit dude;

. 7. A creeper tractor mechanism adapted to be attached to a round wheeltractor body to replace the round heels thereof, com

prising a frame structure including a pairl transversely extending fmembers interposed intermediate the lengthiof said side members, means for pivotally supporting the rear end of each of said .sid'e 'members' upon the rear axle-housing of said tractor body,

. said pivotal supporting means including axle ousing, to support said side members beyond the ends of saidrear axle housing. 6. A creeper tractor mechanism adapted to be'attached to a round wheel tractor body to replace the round Wheels thereof, comprising a frame structure, includingja pair 'of longitudinallyv extending side members,

' transversely extending members, means for connecting sald transverse members and s1de members, said last mentlonedm'eans perm,1t-;

ting independent torsional flexure of said side vmembers, while preventing lateral movement thereof,'means for pivot'ally supporting the rear end of each of said side members upon the rear axle housing of said tractor body beyondthe ends of said rear to replace the round Wheels thereof,

'with said longitudinally extending side members, means for pivotally Z'supporting the rear end of each of said side members' upon the rear axle housing of said tractor body beyond the ends of said rear axle housing-to permit verticaloscillation of said side members with respect to said rear. axle housing.

GEORGE o. JETT.

of longitudinally extending side-members, 

